1. Field of the Invention
The present invention relates to a structure for attaching a heat insulator to an exhaust pipe of a vehicle.
2. Background Art
It is known to attach a heat insulator to an exhaust pipe. For example, Japanese Patent Publication No. 26045/1990 discloses an exhaust pipe and heat insulator construction in which a stay is welded to the exhaust pipe, a band-like member is welded to an inner side of the heat insulator and the band-like member is fastened to the stay by a screw. Further, it is also known that a nut may be directly welded to an exhaust pipe in place of the stay, and a band-like member is directly fastened thereto by a screw.
According to the conventional examples, members to be attached to an exhaust pipe must be welded to both of the exhaust pipe and the heat insulator, or at least any members must be welded on the side of the exhaust pipe. Accordingly, the number of fabrication steps is increased, therefore, resulting in significant manufacturing costs. Further, in the case where the heat insulator is directly fastened to a nut on the exhaust pipe by the screw, an accuracy of a weld position is liable to deteriorate by thermal influence in welding the nut. Therefore, positioning of the heat insulator relative to the exhaust pipe becomes difficult and an assembly operation may be difficult. In addition, to facilitate attachment of the heat insulator, it is conceivable to constitute a screw hole on a side of the heat insulator; however, vibration noise is liable to occur since the exhaust pipe inherently constitutes a vibration source.
It is an object of the present invention to provide a structure of attaching a heat insulator dispensing with welding operation.
In order to solve the above-described problem, according to a first aspect of the present invention, there is provided a structure of attaching a heat insulator to an exhaust pipe. The structure includes a band-like member made to wrap on an outer periphery of the exhaust pipe and the heat insulator for covering the exhaust pipe from an outer side thereof. Both end portions in a length direction of the band-like member and a pair of edge portions of the heat insulator along a length direction of the exhaust pipe are simultaneously coupled to thereby attach the heat insulator to the exhaust pipe via the band-like member.
According to a second aspect of the present invention, there is provided the structure of attaching a heat insulator according to the first aspect, where attaching portions are integrally provided respectively to the pair of edge portions of the heat insulator along the length direction thereof. The attaching portions on a side of the heat insulator are made to overlap on outer sides of a pair of attaching portions provided at the both end portions in the length direction of the band-like member. The respective attaching portions on the side of the heat insulator and on a side of the band-like member are integrally coupled by a bolt and a nut in a state in which a collar is interposed between the attaching portions on the side of the band-like member.
According to the first aspect of the present invention, when the band-like member is firstly made to wrap on the outer periphery of the exhaust pipe, the heat insulator is further made to cover the band-like member from an outer side thereof, and both end portions in the length direction of the band-like member and the pair of edge portions of the heat insulator along the length direction of the exhaust pipe are made to overlap to thereby integrally couple with each other. Moreover, the band-like member is made to wrap and fixed onto a surrounding of the exhaust pipe and the heat insulator is coupled to the band-like member. Therefore, the heat insulator is attached to the exhaust pipe via the band-like member.
Therefore, welding attaching members to the heat insulator and the exhaust pipe as in the conventional structure is not required. The band-like member can be made separate from the heat insulator and the exhaust pipe until the attaching operation. Accordingly, the conventional welding process is eliminated, therefore, reducing the number of fabrication steps in assembling the heat insulator and the exhaust pipe. This results in enhanced fabrication performance and enables a reduction in manufacturing costs.
Moreover, by eliminating the welding operation, a deterioration in accuracy at the attaching portion caused by welding can be prevented. Moreover, according to the present invention the requirement of providing a screw hole in the heat insulator is eliminated; therefore, vibration as a result of the exhaust pipe does not occur.
According to the second aspect of the present invention, when the attaching portions are respectively provided at the both end portions in the length direction of the band-like member and the pair of edge portions of the heat insulator along the length direction of the exhaust pipe, the attaching members are made to overlap each other and fastened together by the bolt and the nut in a state in which the collar is interposed between the attaching portions on the side of the band-like member, thus, the heat insulator can easily be integrated to the exhaust pipe. In this case, by interposing the collar, the attaching portions can easily be attached even when there is deviation in accuracy of a dimension between the respective attaching portions.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention are given by way of illustration only, since various changes and modifications within the sprit and scope of the invention will become apparent to those skilled in the art from this detailed description.